Direct Photocatalyzed Hydrogen Atom Transfer (HAT) for Aliphatic C–H Bonds Elaboration

Chemical Reviews, Год журнала: 2021, Номер 122(2), С. 1875 - 1924

Опубликована: Авг. 6, 2021

Direct photocatalyzed hydrogen atom transfer (d-HAT) can be considered a method of choice for the elaboration aliphatic C–H bonds. In this manifold, photocatalyst (PCHAT) exploits energy photon to trigger homolytic cleavage such bonds in organic compounds. Selective bond may achieved by judicious abstractor (key parameters are electronic character and molecular structure), as well reaction additives. Different classes PCsHAT available, including aromatic ketones, xanthene dyes (Eosin Y), polyoxometalates, uranyl salts, metal-oxo porphyrin tris(amino)cyclopropenium radical dication. The processes (mainly C–C formation) most cases carried out under mild conditions with help visible light. aim review is offer comprehensive survey synthetic applications d-HAT.

Язык: Английский

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Transition-Metal-Catalyzed, Coordination-Assisted Functionalization of Nonactivated C(sp³)–H Bonds

Chemical Reviews, Год журнала: 2021, Номер 121(24), С. 14957 - 15074

Опубликована: Окт. 29, 2021

Transition-metal-catalyzed, coordination-assisted C(sp3)–H functionalization has revolutionized synthetic planning over the past few decades as use of these directing groups allowed for increased access to many strategic positions in organic molecules. Nonetheless, several challenges remain preeminent, such requirement high temperatures, difficulty removing or converting groups, and, although metals provide some reactivity, employing outside palladium. This review aims give a comprehensive overview coordination-assisted, transition-metal-catalyzed, direct nonactivated bonds by covering literature since 2004 order demonstrate current state-of-the-art methods well limitations. For clarity, this been divided into nine sections transition metal catalyst with subdivisions type bond formation. Synthetic applications and reaction mechanism are discussed where appropriate.

Язык: Английский

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Recent advances in organic electrosynthesis employing transition metal complexes as electrocatalysts

Science Bulletin, Год журнала: 2021, Номер 66(23), С. 2412 - 2429

Опубликована: Июль 13, 2021

Язык: Английский

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Cobalt-Catalyzed Enantioselective C–H Annulation with Alkenes

ACS Catalysis, Год журнала: 2023, Номер 13(7), С. 4250 - 4260

Опубликована: Март 13, 2023

Herein, we disclose an efficient cobalt-catalyzed enantioselective C–H activation and annulation of benzamides with alkenes. This transformation is facilitated via the commercially available cobalt(II) catalyst in presence easily prepared chiral salicyl-oxazoline (Salox) ligand, which provides facile access to (R) or (S) enantiomers dihydroisoquinolone derivatives. It noticeable that reaction proceeded efficiently within extremely short time from 10 30 min under mild conditions. A broad range alkenes bear various functional substituents have been shown good compatibility deliver targeted products high yields enantioselectivities (51 examples, up 98% yield 99% ee). The gram scale experiment removal directing group further demonstrate practicability this protocol potential industrial applications. Density theory calculations elucidate mechanism, spin-state change olefin insertion step accelerates subsequent C–N reductive elimination, identified as stereo-determining step. AIM analysis indicates π interactions are vital for controlling switching stereoselectivity.

Язык: Английский

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Cobalt‐Catalyzed Oxidative C−H Activation: Strategies and Concepts

ChemSusChem, Год журнала: 2020, Номер 13(13), С. 3306 - 3356

Опубликована: Фев. 17, 2020

Inexpensive cobalt-catalyzed oxidative C-H functionalization has emerged as a powerful tool for the construction of C-C and C-Het bonds, which offers unique potential transformative applications to modern organic synthesis. In early stage, these transformations typically required stoichiometric toxic transition metals sacrificial oxidants; thus, formation metal-containing waste was inevitable. contrast, naturally abundant molecular O2 more recently been successfully employed green oxidant in cobalt catalysis, thus considerably improving sustainability such transformations. Recently, significant momentum gained by use electricity sustainable environmentally benign redox reagent functionalization, thereby preventing consumption cost-intensive chemicals while at same time addressing considerable safety hazards related oxygen combination with flammable solvents. Considering unparalleled aforementioned approaches synthesis, this Review summarizes recent progress activation until 2020.

Язык: Английский

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Catalytic addition of C–H bonds across C–C unsaturated systems promoted by iridium(i) and its group IX congeners

Chemical Society Reviews, Год журнала: 2020, Номер 49(20), С. 7378 - 7405

Опубликована: Янв. 1, 2020

Transition metal-catalyzed hydrocarbonations of unsaturated substrates have emerged as powerful synthetic tools for increasing molecular complexity in an atom-economical manner. Although this field was traditionally dominated by low valent rhodium and ruthenium catalysts, recent years, there been many reports based on the use iridium complexes. In cases, these reactions a different course from those their homologs, even allow performing otherwise inviable transformations. review we aim to provide informative journey, early pioneering examples field, most them other metals than iridium, transformations catalyzed designed Ir(i) The is organized type C-H bond that activated (with C sp2, sp or sp3), well C-C partner used hydrocarbonation (alkyne, allene alkene). Importantly, discuss mechanistic foundations methods highlighting differences previously proposed processes related metals, particularly same group (Co Rh).

Язык: Английский

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Green strategies for transition metal-catalyzed C–H activation in molecular syntheses

Organic Chemistry Frontiers, Год журнала: 2021, Номер 8(17), С. 4886 - 4913

Опубликована: Янв. 1, 2021

Sustainable strategies for the activation of inert C–H bonds towards improved resource-economy.

Язык: Английский

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Cobalt-catalyzed dehydrogenative functionalization of alcohols: Progress and future prospect

Coordination Chemistry Reviews, Год журнала: 2021, Номер 451, С. 214257 - 214257

Опубликована: Окт. 28, 2021

Язык: Английский

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Transition Metal Promoted Cascade Heterocycle Synthesis through C−H Functionalization

Chemistry - A European Journal, Год журнала: 2020, Номер 26(44), С. 9749 - 9783

Опубликована: Июнь 18, 2020

Sequential, domino and tandem reactions could be defined as a sequence of synthetic transformations that occur one after the other, in same reaction flask. This Review highlights recent advances at overlap two worlds: transition-metal mediated C-H activation trigger cascade reaction, for heterocycles synthesis. To shed some light on this intricate "middle-earth", focus was put mechanism rather than type metal or chronological order reaction. The aim is to separate, then highlight, true initiated by activation, compared other examples functionalization heterocycle syntheses.

Язык: Английский

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C–H bond functionalization by high-valent cobalt catalysis: current progress, challenges and future perspectives

Chemical Communications, Год журнала: 2021, Номер 57(83), С. 10827 - 10841

Опубликована: Янв. 1, 2021

Over the last decade, high-valent cobalt catalysis has earned a place in spotlight as valuable tool for C-H activation and functionalization. Since discovery of its unique reactivity, more attention been directed towards utilization an alternative to noble metal catalysts. In particular, Cp*Co(III) complexes, well simple Co(II) Co(III) salts combination with bidentate chelation assistance, have extensively used development novel transformations. this review, we demonstrated existing trends functionalization methodology using highlighted main challenges overcome, perspective directions, which need be further developed future.

Язык: Английский

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